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Biology LibreTexts

3.9: Simmons Citrate Agar

  • Page ID
    14687
  • Simmons Citrate Agar is a defined medium that tests for an organism's ability to use citrate as its carbon source and ammonia as its nitrogen source. Only bacteria that can transport citrate into the cell from the medium grow well in Citrate Agar.

    Procedure
    1. Obtain a slant of Simmons Citrate Agar.
    2. Using an inoculating needle, stab your assigned organism into the medium, then zigzag the needle back and forth up the surface of the slant.
    3. Incubate the tube for at least 48 hours.
    4. After the incubation period, examine the slant.
    Interpretation

    In a positive test, there will be heavy growth and the slant will turn royal blue.

    3.9.png

    Positive Result